Secondary Electron Emission & Field Emission of Imogolite

Abstract

Imogolite, hydrated alumino-silicate that derives considerable microporosity from a nanometer-sized (~2 nm) tubular structure, has been tested to measure its secondary electron emission and field emission property. Secondary electron emissions(SEE) of pure imogolite and MgO sputtered imogolite were measured at 5*10-6 torr and SEE yields(δ) of them varies 1.2 to 4.5. An imogolite cathode for field emission was fabricated by coating on Si substrate. Imogolites have been tested to measure their field emission(FE) properties and electrical conductivities. The field emissions from imogolite films are found to follow the Fowler-Nordheim formula, and the measured turn-on fields are at the range of 2~3 V/μm.